U.S. patent number 10,058,180 [Application Number 14/422,916] was granted by the patent office on 2018-08-28 for chair, in particular office chair.
This patent grant is currently assigned to Haworth, Inc.. The grantee listed for this patent is Haworth GmbH. Invention is credited to Simon Desanta.
United States Patent |
10,058,180 |
Desanta |
August 28, 2018 |
Chair, in particular office chair
Abstract
Chair, more especially an office chair, comprising a seat plate
(34) which is arranged on an undercarriage (12) and a backrest (14)
which in the manner of a so called synchronous mechanism permit a
synchronous movement of seat plate (34) and backrest (14),
characterized in that the seat plate (34) is mounted laterally
tiltable and the backrest includes two backrest supports (22, 24)
whose lower ends are mounted pivotally independently of each other
on the undercarriage (12) and are coupled in movement to the seat
plate (34) in such a manner that by rearward pivoting of the
support (22, 24) one side of the seat plate (34) is pressed down on
the same side and the opposite side thereof is raised.
Inventors: |
Desanta; Simon (Borgholzhausen,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Haworth GmbH |
Ahlen |
N/A |
DE |
|
|
Assignee: |
Haworth, Inc. (Holland,
MI)
|
Family
ID: |
49000478 |
Appl.
No.: |
14/422,916 |
Filed: |
August 16, 2013 |
PCT
Filed: |
August 16, 2013 |
PCT No.: |
PCT/EP2013/067130 |
371(c)(1),(2),(4) Date: |
February 20, 2015 |
PCT
Pub. No.: |
WO2014/029696 |
PCT
Pub. Date: |
February 27, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20150245713 A1 |
Sep 3, 2015 |
|
Foreign Application Priority Data
|
|
|
|
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Aug 23, 2012 [DE] |
|
|
10 2012 107 778 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47C
1/032 (20130101); A47C 1/03255 (20130101); A47C
7/40 (20130101); A47C 7/448 (20130101); A47C
7/44 (20130101); A47C 7/024 (20130101); A47C
7/14 (20130101) |
Current International
Class: |
A47C
3/025 (20060101); A47C 7/02 (20060101); A47C
7/14 (20060101); A47C 7/40 (20060101); A47C
7/44 (20060101); A47C 3/026 (20060101); A47C
1/032 (20060101) |
Field of
Search: |
;297/285,292,293,296,297,314 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
International Search Report for International Application
PCT/EP2013/067130, dated Nov. 7, 2013. cited by applicant .
Preliminary Report on Patentability for International Application
PCT/EP2013/067130, dated Dec. 11, 2014. cited by applicant .
Written Opinion from Examining Authority for International
Application PCT/EP2013/067130, dated Sep. 23, 2014. cited by
applicant .
Written Opinion from the Search Authority for International
Application PCT/EP2013/067130, dated Aug. 30, 2013. cited by
applicant.
|
Primary Examiner: White; Rodney B
Attorney, Agent or Firm: Warner Norcross + Judd LLP
Claims
The invention claimed is:
1. An office chair (10), comprising: a seat plate (34) which is
arranged on an undercarriage (12); a backrest (14); and a
synchronous mechanism permitting a synchronous movement of the seat
plate (34) and the backrest (14), wherein the seat plate (34) is
mounted laterally tiltable about a longitudinal tilt axis (B) that
extends in a forward direction from the backrest, and the backrest
includes two backrest supports (22, 24), the backrest supports
having lower ends that are mounted pivotally independently of each
other on the undercarriage (12) and are coupled in movement to the
seat plate (34) in such a manner that by rearward pivoting of one
of the supports (22, 24) a first side of the seat plate (34) is
pressed down so as to be tilted about the tilt axis (B) to a
position below the tilt axis (B) and a second side opposite the
first side is raised to a position above the tilt axis (B), wherein
a tilt shaft extends in a longitudinal direction along tilt axis
(B) for the lateral tilting of the seat plate (34) and lies in a
vertical plane between the backrest supports (22, 24).
2. The office chair according to claim 1, wherein the lower ends of
the backrest supports (22, 24) are connected pivotally about a
common horizontal pivot axis (A) to a base (20) of the
undercarriage (12).
3. The office chair according to claim 2, wherein on the first side
and the second side beneath the seat plate (34), a set of bearings
(44) are provided in which the lower ends of the backrest supports
(22, 24) lie in a region behind the pivot axis (A) thereof.
4. The office chair according to claim 3, wherein the seat plate
(34) is pivotal together with the lower ends of the backrest
supports (22, 24) about the pivot axis (A) thereof.
5. An office chair, comprising: a seat plate (34) which is arranged
on an undercarriage (12); a backrest (14); and a synchronous
mechanism permitting a synchronous movement of the seat plate (34)
and the backrest (14), wherein the seat plate (34) is mounted
laterally tiltable about a tilt axis (B) and the backrest includes
two backrest supports (22, 24), the backrest supports having lower
ends that are mounted pivotally independently of each other on the
undercarriage (12) and are coupled in movement to the seat plate
(34) in such a manner that by rearward pivoting of the support (22,
24) a first side of the seat plate (34) is pressed down so as to be
tilted about the tilt axis (B) and a second side opposite the first
side is raised, wherein the lower ends of the backrest supports
(22, 24) are connected pivotally about a common horizontal pivot
axis (A) to a base (20) of the undercarriage (12) and wherein a
tilt shaft extends along tilt axis (B) for the lateral tilting of
the of the seat plate (34) and lies in a vertical plane between the
backrest supports (22, 24), wherein on the first side and the
second side beneath the seat plate (34), a set of bearings (44) are
provided in which the lower ends of the backrest supports (22, 24)
lie in a region behind the pivot axis (A) thereof, wherein the seat
plate (34) is pivotal together with the lower ends of the backrest
supports (22, 24) about the pivot axis (A) thereof wherein in a
rear region of the undercarriage (12) a bearing member (36) is
mounted which is tiltable about the pivot axis (A) of the backrest
supports (22, 24) and supports a tilt shaft aligned along the tilt
axis (B) of the seat plate (34).
6. The office chair according to claim 5, wherein the seat plate
(34) is arranged in a rear region of the seat surface and in a
front region of the seat surface a front seat plate (32) is
arranged, the front seat plate (32) having opposing sides, wherein
a leg springs (48) extends rearwardly from each of said sides to
support the rear seat plate (34) on both of the sides from
below.
7. The office chair according to claim 6, wherein the front seat
plate (32) is carried by a front bearing member (50), the front
bearing member having a rear end that is articulately connected to
a front end of the bearing member (36), the front bearing member
having a front end that is articulately connected to the front end
of the base (20) lying therebelow via a connection member (52)
which in its rear end receives the horizontal pivot axis (A) of the
supports (22, 24).
8. The office chair according to claim 1, wherein the lower ends of
the backrest supports (22, 24) are formed by legs (30) angled
forwardly in an L shape, the legs (30) having front portions (38)
which are connected pivotally about substantially vertically
directed axes (C) of rotation to the respective support (22, 24)
and the legs (30) having front ends which accommodate the
horizontal pivot axis (A) of the supports (22, 24).
9. An office chair, comprising: a seat plate (34) which is arranged
on an undercarriage (12); a backrest (14); and a synchronous
mechanism permitting a synchronous movement of the seat plate (34)
and the backrest (14), wherein the seat plate (34) is mounted
laterally tiltable and the backrest includes two backrest supports
(22, 24), the backrest supports having lower ends that are mounted
pivotally independently of each other on the undercarriage (12) and
are coupled in movement to the seat plate (34) in such a manner
that by rearward pivoting of the support (22, 24) a first side of
the seat plate (34) is pressed down and a second side opposite the
first side is raised, wherein the backrest supports (22, 24) are
connected in an upper region by a transverse member (54), the
transverse member having ends that are articulately connected to
the backrest supports (22, 24), the ends forming connection points
(56, 58) between the backrest supports (22, 24) and the transverse
member, wherein a spacing is defined between the connection points
(56, 58), the articulate connection of the transverse member to the
backrest supports (22, 24) keeping the spacing between the
connection points (56, 58) constant without otherwise restricting a
relative movement of the backrest supports (22, 24) with respect to
each other.
10. The office chair according to claim 9, wherein the transverse
member (54) is formed as a rod with variable length for adjusting
the spacing between the connection points (56, 58) at which the rod
(54) is connected by ball joints (60) to the backrest supports
(22,24).
Description
BACKGROUND OF THE INVENTION
The invention relates to a chair, more especially an office chair,
comprising a seat plate which is arranged on an undercarriage and a
backrest which in the manner of a so called synchronous mechanism
permit a synchronous movement of backrest and seat plate.
Such chairs are known in numerous constructional forms. They have a
coordinated movement of backrest and seat plate. This means that
when the user leans against the backrest the latter and the seat
plate assume a position which corresponds substantially to a lying
or leant back position. The result of such a synchronous movability
is that when working the user can sit upright in a forwardly
inclined position whereas in the leant back position he assumes a
position of rest.
Such a movement coupling of seat plate and backrest is generally
referred to as synchronous mechanism. Chairs which are equipped
with such a mechanism have the advantage that they adjust
themselves substantially automatically to the weight of the user
without any manual adjustment being necessary. The cooperation of
seat and backrest in the sense described takes place independently
of the weight of the user.
The hitherto known chairs with synchronous mechanism already afford
a relatively high sitting comfort. However, the hitherto known
chair constructions cannot adjust themselves to load shifts from
one side of the seat surface to the other or to forces acting on
one side of the backrest. However, such unequal loads frequently
occur in the use of office chairs. For ergonomic reasons it would
be desirable to accommodate corresponding loads so that the chair
can adapt itself to a laterally changed posture of the user. Known
chairs however do not afford any such possibilities.
The problem underlying the present invention is therefore to
provide a chair having a synchronous mechanism of the type
mentioned at the beginning which can adapt itself to different
loads on both sides of the chair and in this manner further
increases the sitting comfort.
This problem is solved according to the invention by a chair having
the features of claim 1.
The seat plate of the chair according to the invention is mounted
laterally tiltable, i.e. it can be tilted about a longitudinal axis
of the chair, said axis extending substantially forwardly from the
backrest. This tilting can be combined with a tilting movement
about a transverse axis of the chair in the sense of the hitherto
known synchronous mechanism. The seat plate is coupled to two
backrest supports whose lower ends are pivotally mounted on the
undercarriage in such a manner that that they can be pivoted
independently of each other and can assume different inclinations.
By the movement coupling between the seat plate and the supports
said seat plate is pressed down on the same side by a rearward
pivoting of the support whilst the opposite side thereof is
raised.
This movement coupling represents a considerable extension of the
hitherto known principle of the synchronous mechanism and
corresponds to a greater extent to an ergonomic sitting position
because crosswise acting loads on the seat plate and the backrest
can be compensated by the mechanism of the chair.
According to a preferred embodiment of the invention the lower ends
of the backrest supports are connected pivotally about a common
horizontal axis to a base of the undercarriage and the tilt axis
for the lateral tilting of the seat plate lies in a vertical plane
between the backrest supports. Said base can be a part at the upper
end of the central column of the undercarriage which is mounted
vertically adjustably on the column and is stationary with respect
to the movability of the backrest and the seat plate.
According to a further preferred embodiment on both sides of the
seat plate bearings are provided which receive the lower ends of
the backrest supports in a region behind the pivot axis thereof.
Said bearings can for instance engage round the lower ends of the
supports laterally and from below, for example such that the
support ends lie in the bearings on resilient pads. If one of the
two backrest supports is pivoted rearwardly about its horizontal
axis a pressure is exerted downwardly on the bearing assembly and
presses the seat plate downwardly on the corresponding side. This
leads to the desired lateral tilting of the seat plate.
Preferably the seat plate is pivotal together with the lower ends
of the backrest supports about the horizontal pivot axis thereof.
Thus, in this case the seat plate can be not only laterally tilted
but can also execute a pivot movement about a transverse axis of
the chair so that on uniform load on the two backrest supports it
can tilt down rearwardly.
Further preferably, in the rear region of the undercarriage a
bearing member is mounted which is tiltable about the pivot axis of
the backrest supports and supports the pivot shaft of the seat
plate. This bearing member if thus tilted together with the
backrest supports and the seat plate about a transverse axis.
According to a further preferred embodiment of the present
invention the seat plate is arranged in the rear region of the seat
surface and in the front region of the seat surface a front seat
plate is arranged, and from said seat plate on both sides of the
chair leg springs extend rearwardly and support the rear tiltable
seat plate from below on both sides. The rear seat plate can then
execute the tilting movement only against the resistance of the leg
springs which when no load is present keep the seat plate in a
balanced position.
According to a further preferred embodiment of the present
invention the front seat plate is carried by a front bearing member
whose rear end is articulately connected to a front end of the
bearing member and whose front end is articulately connected to the
front end of the base of the undercarriage lying therebelow via a
connection member which at its rear end receives the pivot shaft of
the supports. The front bearing member, the bearing member arranged
therebehind and connected articulately thereto for supporting the
rear seat plate and the front connecting member are then connected
to the base to form a quadrilateral whose corners are formed by
articulations which permit the front bearing member, the rear
bearing member and the connecting member to be adjusted with
respect to each other so that they can form different angles to
each other.
According to a further preferred embodiment of the invention the
lower ends of the backrest supports are formed by legs angled
forwardly in L shape, the front portions of which are connected
pivotally about substantially vertically directed axes of rotation
to the remainder of the respective support and the front ends of
which accommodate the horizontal pivot shafts of the supports.
Thus, in this case the backrest supports are not only pivotal with
respect to the undercarriage about a common horizontal axis; in
addition, the spacing of their vertical legs can be adjusted by a
pivoting thereof with respect to the front portions of the
horizontal legs mounted on the undercarriage.
More preferably the backrest supports are connected in an upper
region by a transverse member whose ends are articulately connected
to the supports in such a manner that the spacing between the
connection points on the supports is kept constant without
otherwise restricting a relative movement of the supports with
respect to each other. Said transverse member effects a movement
coupling of the upper portions of the backrest supports to each
other. If one of the supports is tilted this leads automatically to
a tilt movement coupled thereto of the other support. Thus, a
pressure load on one side acting on the backrest causes a counter
pressure on the other side of the backrest.
According to a further preferred embodiment said transverse member
is formed as a rod with variable length for adjusting the spacing
between the connection points at which the rod is connected by ball
joints to the supports. The length of the transverse member can
thus be set by the user for adaptation to the user's own body
dimensions.
Hereinafter a preferred example of embodiment of the invention will
be described in detail with the aid of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an office chair illustrating a
preferred embodiment of the present invention;
FIGS. 2 and 3 show the office chair or FIG. 1 in different
positions;
FIG. 4 is a side view of the office chair according to the present
embodiment in a position corresponding to FIG. 1;
FIG. 5 shows the office chair in a side view on assuming a position
corresponding to FIG. 2;
FIGS. 6, 7 and 8 are rear views of the office chair of the
preceding Figures;
FIG. 9 is a detail view of the mechanism of the present preferred
embodiment of the office chair according to the invention; and
FIG. 10 is an exploded view of some of the mechanical components
illustrated in FIG. 9.
DETAILED DESCRIPTION
The chair illustrated in FIGS. 1 to 7 is an office chair 10 which
comprises in conventional manner an undercarriage 12 which bears a
seat surface, and a backrest 14 which is mounted at the rear side
of the chair 10. The terms "front" and "rear" as well as "lateral"
are with reference to the usual position of use of the chair. The
undercarriage 12 is provided in usual manner with a ring of rollers
16 which are mounted on arms extending from a vertically adjustable
central column 18. The components of the undercarriage 12 are known
and are not part of the present invention.
Mounted at the upper end of the central column 18 is a
substantially plate-shaped base 20 of the undercarriage 12, said
base being connected to further movable components of the chair 10.
The backrest 14 is pivotally connected to the rear end of the base
20 so that the backrest 14 can be pivoted rearwardly with respect
to the rear end of the base 20 as is illustrated in FIGS. 2 and 5.
The pivot axis of the backrest 14 is designated in the drawings by
the letter A. The axis A extends horizontally in the transverse
direction of the chair 10.
The backrest 14 includes in detail two backrest supports 22, 24
which are connected by a common backrest surface 26. Said backrest
area 26 has a certain elasticity which does not fundamentally
impair the pivoting of the two backrest supports 22,24 on both
sides of the chair 10 but merely somewhat limits the pivoting
range. This does not impair the function according to the invention
of the chair 10.
The backrest supports 22, 24 on both sides of the chair 10 are
mounted on separate pivot bearings on the horizontal pivot axis A.
Said pivot bearings are located at the rear side of the base 20
directly adjacent each other, as will be explained in more detail
hereinafter, but on the common axis A. The supports 22, 24 can thus
assume different angles of inclination. Each of the supports is
formed substantially
L-shaped and has a rear vertical leg 28 and a lower leg 30 which in
FIGS. 1 and 4 is substantially horizontal and the front end of
which leads to the respective pivot bearing. The length of the
horizontal leg 30 provides a rearward offsetting of the backrest
surface 26 with respect to the seat surface and the axis A and thus
for an adequately comfortable sitting position. Moreover, it is
obvious that the backrest area 26 can be cushioned or configured in
any other desired manner to ensure adequate sitting comfort.
The seat area of the chair 10 is formed by two seat plates, that is
a front seat plate 32 arranged at the front edge of the chair 10
and a rear seat plate 34 located between the front seat plate 32
and the backrest 14. Whereas the front seat plate 32 is
substantially stationary, the rear seat plate 34 is movable to a
great extent, as will be explained in detail hereinafter. It is
disposed above the horizontal pivot axis A and bridges the entire
width of the seat surface.
On a rearward inclination of the backrest 14 the rear seat plate 34
is tilted rearwardly and downwardly, as can be seen clearly in
FIGS. 2 and 5. The seat plate 34 thus follows the movement of the
backrest supports 22, 24 and is coupled in movement to the latter.
Thus, like the backrest 14 the seat plate 34 is pivoted about the
horizontal pivot axis A.
The perspective rear view in FIG. 9 and the exploded illustration
in FIG. 10 show how the seat plate 34 is coupled in movement to the
backrest supports 22, 24. The seat plate 34 is mounted laterally
tiltable, i.e. in the left-right direction, about a tilt axis B.
The tilt axis B extends directly beneath the actual seat area and
lies in a vertical symmetry plane of the chair 10 which in turn is
perpendicular to the horizontal pivot axis A of the backrest 14. In
the inoperative position of the chair in FIGS. 1, 4 and 7 the tilt
axis B is horizontal.
The seat plate 34 is mounted tiltable about the axis B on a bearing
member 36 which itself is tiltable about the pivot axis A. The seat
plate 34 is therefore pivotal both about the horizontal axis A and
about the tilt axis B, The tilt axis B is itself tilted out of the
horizontal position when the bearing member 36 is pivoted about the
pivot axis A.
The articulate connection between the backrest supports 22, 24 and
the stationary part 20 of the undercarriage 12 is effected via
front portions 38 of the forwardly angled legs 30 of the supports
22, 24. These front portions 38 are formed as pairs of plates 40,
42 (see FIG. 10) which are arranged parallel above each other and
which enclose from above and below the forwardly directed ends of
the remaining portions of the horizontal legs 30. As can be seen in
particular in FIG. 7 the front portions 38 are articulately
connected to the remaining portion of the respective support 22,
24, this being done via vertically disposed rotation axes C. In
particular the vertical legs 28 of the supports 22, 24 are thus
pivotally mounted at the rear side of the chair 10. The horizontal
pivot axis A of the backrest 14 extends through the front ends of
the portions 38.
Provided on both sides beneath the seat plate 34 are bearings 44
which are configured as members formed L-shaped at the underside of
the seat plate 34. The horizontal legs of these members point
towards each other and engage laterally into the portions 38
between the upper and lower plates 40 and 42. The upper plates 42
thus lie in the bearings 44, that is on pads 46 provided there for
dampening.
Since the portions 38 can be pivoted independently of each other
about the axis A, on the two sides of the chair 10 a different
pressure can be transmitted via the bearing means 44 to the seat
plate 34 and this leads to the seat plate 34 being tilted laterally
about the tilt axis B due to this one-sided load. If for example in
accordance with FIGS. 3 and 7 the right backrest support 22 is
pivoted rearwardly, its horizontal leg 30 will be pressed
downwardly. When this happens, via the upper plate 42 the front
portion 38 of the leg 30 exerts a pressure on the on the right
bearing member 44 of the seat plate 34 so that said seat plate 34
is pressed down on this side whilst the opposite left side of the
seat plate is raised. In other words the rearward pivoting of a
support 22, 24 on one side of the chair 10 involves a pressing down
of the rear seat plate 34 on the same side and a raising of the
opposite end of the seat plate 34 on the other side. The backrest
supports 22, 24 hereby assume different inclination positions. FIG.
8 shows the situation when a pressure is exerted on the left side
of the seat plate 34.
The unilateral lowering of the seat plate takes place against the
pressure of one end of a leg spring 48 which extends laterally
rearwardly from the front seat plate 34 and on which the respective
end of the rear seat plate 34 is mounted. Thus, the seat plate 34
on reduction of the pressure from above has the tendency to return
to its horizontal position.
According to FIG. 10 a central part of the leg spring 48 is mounted
in a front bearing member 50 which also carries the front seat
plate 32 and is formed integrally with the latter. The rear end of
said front bearing member 50 is connected pivotally about a
horizontal pivot axis D to a front end of the bearing member 36
which carries the rear seat plate 34. At its front end the front
bearing member 50 is articulately connected via a connector 52 to
the front end of the base 20, lying therebelow, of the
undercarriage 12. The articulation axis for connecting the front
upper end of the connector 52 to the front bearing member 50 is
denoted by the letter E whilst the articulation axis between the
connector 52 and the base 20 is denoted by F. The axes A, D, E and
F define a quadrilateral which approximately forms a parallelogram.
This construction effects that on tilting of the bearing member 36
together with the rear seat plate 34 a tensile force is exerted on
the front bearing member 50 with the front seat plate 32 and the
latter is slightly raised, as becomes clear on comparison of FIGS.
4 and 5. The front seat plate however retains its horizontal
position here.
Although the lower ends of the backrest supports 22, 24 are mounted
independently of each other about the pivot axis A, in their upper
region the supports 22,24 are coupled in movement; this is done
according to FIGS. 6 to 9 by a transverse member 54 whose ends 56,
58 are articulately connected to the vertical legs 28 of the
supports 22, 24 at about half the height of the backrest 14. This
articulate connection is by ball joints 60. The transverse member
54 ensures that the distance between the connection points 56, 58
to the supports 22, 24 is kept constant without otherwise
restricting the movement of the supports 22, 24 relative to each
other. In particular, the pivoting of the supports 22, 24 in
opposite directions remains possible. The transverse member 54 here
assumes an inclined position and the vertical legs 28 of the
supports 22, 24 can come closer to each other. This is made
possible by a slight pivoting of the rear portions of the supports
22, 24 about the vertical pivot axes C with respect to the front
portions 38.
In the movement sequence described above during the use of the
chair 10 the distance between the articulation points of the
transverse member 54 remains constant. However, the length of the
transverse member 54 can be adjusted by the user employing a
suitable mechanism so that the tension between the backrest
supports 22, 24 is variable, This mechanism may for example include
a spindle drive inside the transverse member 54.
* * * * *